We shall continue our experiments on the pathogenesis of Creutzfeldt-Jakob disease in small rodents. The presence of viremia in man will be studied. In a timed experiment the appearance of titratable infectious agent in spleen and brain will be investigated. We shall also study the sequence of events in dendrites and correlate these changes with the vacuolation observed in the CNA of infected animals. We shall attempt to release the Creutzfeldt-Jakob agent from membrane rich highly infective brain fractions by using non denaturating detergents.